Bell Upgrade Option?

So I've got $250 of credit accumulated to go towards a phone upgrade and I was wondering how this actually works? For instance, I was looking at the upgrade option online and it basically just takes $250 off of the regular no-contract price of the phone, is this how it works? For instance, the upgrade lets me take $250 off of the Blackberry Curve ($500+ regular price) and drops it down to $200-something WITH a 3-year contract. My confusion is: if this is right, how is this a "deal" or an upgrade at all when a new customer can get a Curve for like $99.99 on a 3-year contract?

Don't do that!

Contracts advertised on the website are for NEW* clients only (new as in either brand new client, prepaid/postpaid conversion, or non-contract clients).

The hardware upgrade credit on your account is for existing clients, or clients who are already on a contract. Even if your contract is not yet over, you still have a certain credit amount available if you renew your agreement. If you have a "big account" (i.e. expensive monthly bill) your loyalty credit might even cover the entire cost of a device, but either way, this credit is only available if you renew your agreement.